Homeostasis
The body keeps internal conditions steady.
About this topic
Homeostasis is the maintenance of a stable internal environment despite external changes: body temperature (~37 °C), blood glucose, water balance and pH. It works through negative feedback: a receptor detects a change, a control centre (often the brain) processes it, and effectors act to restore the set point.
If too hot, sweating and vasodilation cool you; if cold, shivering and vasoconstriction warm you. Failure of homeostasis can cause illness, for example diabetes when glucose control fails.
On a hot day, your temperature sensors in the hypothalamus detect warming, and the body sweats and widens skin blood vessels to lose heat; on a cold day it shivers and narrows vessels. If the system fails, hypothermia or heat stroke may follow. Control systems have a set point, a receptor, a control centre and an effector.
Negative feedback reverses changes to keep conditions steady, like a thermostat in a house. Positive feedback is rarer, and amplifies change, as in contractions during childbirth. Students often say homeostasis keeps conditions constant; more exactly, it keeps them within a narrow range with small fluctuations. Kidney, liver, lungs and skin all contribute, showing how organ systems cooperate.
Key ideas
- Negative feedback
- Temperature, glucose, water
- Sweating cools you
Quick check
Use cases: where Homeostasis helps
- Homework: review the key idea behind Homeostasis before you start a problem set.
- Exam revision: use the quick check to test whether you can recall Homeostasis without notes.
- Visual learning: play with the interactive lab to see how Homeostasis changes when you adjust its inputs.
- Teaching a friend: explain Homeostasis in your own words, then compare your version with the key ideas.
Biology underpins medicine, farming, conservation and biotechnology.
Frequently asked questions
What is Homeostasis?
The body keeps internal conditions steady.
What will I learn in Homeostasis?
Negative feedback. Temperature, glucose, water. Sweating cools you.
Is Homeostasis part of Biology?
Yes. It is one of 150 Biology topics on LearnViz HighSchoolEdu, with 3 key ideas, a live animation and a quick check.
Does the Homeostasis lab work on a phone or tablet?
Yes. The animation resizes to fit your screen and supports touch, so you can drag, tap and slide with your finger.
How should I study Homeostasis?
Read the summary and key ideas first, play with the interactive lab to see the idea in motion, then answer the quick check. If you get a question wrong, go back to the key idea it tests.
Do I need an account, and is my progress saved?
No account is needed. Marking a topic as learned is saved in your own browser, so it stays on that device and is not sent to a server.